Milling-cutter.



T. R. HELLGRBN.

MILLING GUTTER. APPLIGA'HQN ILED 11:13.20, 1907.

998,174. Patented July, 1911.

NITED STATES PATENT OFFICE.

TOBIAS R. HELLGREN, AURORA, ILLINOIS.

MILLING-CUTTER.

' Specication of Letters Patent.

Patented July 18, 191 1.

To all whom t may concern: Y

Be it known that I, TorAs R. HnLLcREN.l a citizen of the United States, residing at Aurora, in the county of Kane and State Of Illinois, have invented certain new and useful Improvements in Milling-Cutters, of

which the' following is a `specification.

. so construct the cutter that a more rapid 'cutting action will be secured than with previous cutters.

In the drawings- Figure 1 is an edge view of my improved cutter,- and Fig. 2 is a side View of a part of the` same.

It is common in-Inilling cutters to place the teeth upon the periphery of the cutter in a position inclined to the path of movement of the surface of the cutter, and to incline all of the teeth in the same direction making them parallel. It has also been the practice to make all ofthe teeth extend completely across the periphery of the cutter. In my improved cutter I also incline the teeth to the path of movement of the cutter but 'do not incline them all in the same direction, nor do I make all of the teeth extend completely across ,the edge of the cutter. The cutters are made in the form of a circular disk or cylinder. For the purpose of defining the incline and position of the cutting teeth I shall refer to the elements of the c linder upon which the teeth may be consi ered' as superimposed, the elements as geometrically4 defined, being right lines lying in the surface of the cylinder and parallel to the axis thereof. By reference to the drawings, particularly to e' Fig. 1, it will be seen that I have arranged the cutting teeth inpairs, each pair comprising one tooth extending. completely across the edge or face ofthe cutter and the other tooth extending partially across the face-thereof. It will also be observed that fthe' cutting edges of each of the pairs*l of teeth, designated upon the drawing respectively as a, a', b, b', c, c', etc., are parallel, and that the complete teeth of each 'pair of parallel teeth are arranged for- Wardly of the incomplete tooth of the same pair. The teeth of each pair are extended upon the side of the cutter as indicated at a2, b2, c2, etc., and that 'alternate pairs of teeth are extended upon one side of the cutter and the intervening pairs upon the opposite side. Each pair of teeth is continued upon the side of the cutter to which the partial tooth belonging to that pair is adjacent, the partial teeth of alternate pairs being upon one side of the cutter and the partial teeth of the intervening pairs upon the opposite side. l

In operation the cutter is rotated in the direction toward which the cutting teeth zare, directed, that is, considering Fig. 2, in-

the tooth b cuts a narrow shaving preparf.,

ing the way and lessening the burden upon -the following full width tooth a which it will be observed is inclined in the opposite direction to the tooth b. with my improved cutter moving at a peripheral speed of from 45 to 50 feet, I am able to move the table at a much greater speed and make a out of greater depth than -with any prior form of milling cutter moving at the same or any other peripheral speed.l I have also found that the durability of the cutter constructed in accordance with my invention is far greater than that of other cutters and that it may be operated continuously for long periods of time without lbecoming heated to an extent sufficient to be injurious.

` I have illustrated the cutter as being formed of aV single piece of metal with I have found that y integral teeth and while I consider this form 'i advantageous it obviously would be possible to construct a cutter according to my invention with separate teeth mounted upon the disk. I do not desire, therefore, that lmy invention be considered as restricted to either integral or separate teeth, but to cover teeth of the form defined in the claims whetherA ...demolito oi? said Cylinclor, one tooth of each pair xtending only partially' aorosS tho fao@ ot 'the cutter, froci the other tooth of @zich 'pair extending completely across Vtho moe.

It milling cutter provided. upon its l'yoriphornl fargo with oppositoly inclined pairs of Spiral teeth, the tooth of alternate pairs extending toward tho conter on oiposito simios of tho Cutter and one tooth of oooh pair extending oiilj/7 partially across the periphoral face. of the cutter.

4. A iiiillilig cutter provided iilion its poriphoii'ol iluso with oppositely ino-lined pairs of :spiral met@ the teeth oi' alternato noirs extending toward 'tho conter ou oppo- Site sitios of the cutteroifil one tooth of each. pair extending only partially across the por @wrm riplieral face of the outtor, :incl the other tooth extending completely across the face of the cutter.

5. A. milling cutter provided upon its peripheral face with ,oppositoly inclinedV nml intervening teeth extending but par` tizilly across the fficej sill of sfiirl teeth being; inclined to the'r path of mommont mul @zich portial tooth having :in inclination opposite to that of tho completo tooth iiiiiriedintoly holiiiicl it.

'lfllllS HELL@ REN. 1.ll/'itiiess-ios t TVALTER A. SCOTT, lW. T. JONES. 

